Comments

You might try using the "Taper" dial to ease some of the distortion. It is quite sensitive, so work lightly.
None of the built-in morphs affect the length, so you might just have to make a custom morph.
I don't know of any morphs like that, but maybe someone else will

I am using DS 4.5 and am unable to find a taper dial. Is that possibly a Poser feature. I have never created a custom morph, so I will have look into that. I am guessing I could use the Send to Hexagon feature and do it there. (once I learn how of course)

I have tried using the yScale along with the zScale and it just distorts the mesh too badly. At least I can't get it to look good. It is unfortunate that the axes for the neck don't line up with the orientation of the neck. I think it is the only part on the body that is like that.